Oxidation Behavior of Yb_(2)Si_(2)O_(7) Modified SiC/SiC Mini-composites  

Yb_(2)Si_(2)O_(7)改性SiC/SiC复合材料的氧化行为研究

作　　者：MU Shuang MA Qin ZHANG Yu SHEN Xu YANG Jinshan DONG Shaoming 穆爽;马沁;张禹;沈旭;杨金山;董绍明(中国科学院上海硅酸盐研究所,高性能陶瓷与超微结构国家重点实验室,上海200050;中国科学院大学材料与光电研究中心,北京100049)

机构地区：[1]State Key Laboratory of High Performance Ceramics&Superfine Microstructure,Shanghai Institute of Ceramics,Chinese Academy of Sciences,Shanghai 200050,China [2]Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《无机材料学报》2025年第3期323-328,共6页Journal of Inorganic Materials

基　　金：National Natural Science Foundation of China(52222202);National Key R&D Program of China(2022YFB3707700);Project of Shanghai Science and Technology Innovation Action Plan(21511104800);Shanghai Pilot Program for Basic Research-Chinese Academy of Science,Shanghai Branch(JCYJ-SHFY-2021-001);Science Center for Gas Turbine Project(P2022-B-Ⅳ-001-001)。

摘　　要：Silicon-carbide-fiber-reinforced silicon-carbide-ceramic-based matrix(SiC/SiC)composites possess excellent properties such as low density,high strength and high temperature resistance,showing a potential application for structural components in the aerospace field,but their oxidation behavior remains largely unknown.In this study,Yb_(2)Si_(2)O_(7) modified SiC/SiC(SiC/SiC-Yb_(2)Si_(2)O_(7))mini-composites were prepared by introducing Yb_(2)Si_(2)O_(7) as anti-oxidation phase into SiC fiber bundles via Sol-Gel and depositing SiC matrix by chemical vapor deposition(CVD).Influence of Yb_(2)Si_(2)O_(7) on microstructure,mechanical property and oxidation behavior of SiC/SiC mini-composites was investigated.The results showed that after oxidation in air at 1200 and 1400℃for 50 h,the tensile strength retentions of SiC/SiC mini-composites were 77%and 69%,respectively,and the fracture morphology exhibited flat.The Yb_(2)Si_(2)O_(7) introduced by Sol-Gel partially distributed in layers,contributing to the toughening of the material.On the fracture surface,there was interlayer debonding,which extended energy dissipation mechanism of SiC/SiC mini-composites.Tensile strength of SiC/SiC-Yb_(2)Si_(2)O_(7) mini-composites at room temperature was 484 MPa.After oxidation in air at 1200 and 1400℃for 50 h,the tensile strengths decreased to 425 and 374 MPa,resulting in retention rates of 88%and 77%,respectively.It displayed typical non-brittle fracture characteristics.The interface oxygen content of SiC/SiC mini-composites at the fracture surface was higher than that of SiC/SiC-Yb_(2)Si_(2)O_(7) mini-composites,indicating that introduction of Yb_(2)Si_(2)O_(7) could alleviate oxygen diffusion towards the interface,and therefore improve the oxidation resistance of SiC/SiC-Yb_(2)Si_(2)O_(7) mini-composites.碳化硅纤维增强碳化硅陶瓷基(SiC/SiC)复合材料具有低密度、耐高温、高强度等优异性能,在热端部件结构材料领域具有广泛应用前景。本研究通过溶胶-凝胶法在SiC纤维束内引入Yb_(2)Si_(2)O_(7)抗氧化相,并结合化学气相沉积(CVD)法沉积SiC基体,制备了Yb_(2)Si_(2)O_(7)改性SiC/SiC(SiC/SiC-Yb_(2)Si_(2)O_(7))复合材料,讨论了Yb_(2)Si_(2)O_(7)对SiC/SiC复合材料微观结构、力学性能及氧化行为的影响。结果表明,SiC/SiC复合材料经过1200和1400℃空气氧化50 h后的强度保持率分别为77%和69%,拉伸断口处观察到纤维基体平齐断裂。溶胶-凝胶法引入的Yb_(2)Si_(2)O_(7)在基体中部分呈层状分布,层状Yb_(2)Si_(2)O_(7)相有利于材料的增韧,拉伸断口处出现层间脱黏现象,扩展了SiC/SiC复合材料能量耗散机制。SiC/SiC-Yb_(2)Si_(2)O_(7)复合材料的室温拉伸强度为484 MPa,在1200和1400℃空气中氧化50 h后的剩余强度分别为425和374 MPa,强度保持率分别为88%和77%,仍表现出典型的非脆性断裂特征。SiC/SiC复合材料断口处界面氧含量大于SiC/SiC-Yb_(2)Si_(2)O_(7)复合材料,说明引入Yb_(2)Si_(2)O_(7)缓解了氧向界面内的扩散,改善了SiC/SiC-Yb_(2)Si_(2)O_(7)复合材料的抗氧化性能。

关 键 词：SiC/SiC mini-composite matrix modification Yb_(2)Si_(2)O_(7) oxidation behavior 

分 类 号：TQ174[化学工程—陶瓷工业]